/*
 * include/irc_reslib.h
 *
 * $Id: reslib.h 26094 2008-09-19 15:33:46Z androsyn $
 */

#ifndef _CHARYBDIS_RESLIB_H
#define _CHARYBDIS_RESLIB_H

/* Here we define some values lifted from nameser.h */
#define NS_NOTIFY_OP 4
#define NS_INT16SZ 2
#define NS_IN6ADDRSZ    16
#define NS_INADDRSZ      4
#define NS_INT32SZ 4
#define NS_CMPRSFLGS    0xc0
#define NS_MAXCDNAME 255
#define QUERY 0
#define IQUERY 1
#define NO_ERRORS 0
#define SERVFAIL 2
#define NXDOMAIN 3
#define T_A 1
#define T_AAAA 28
#define T_PTR 12
#define T_CNAME 5
#define T_NULL 10
#define C_IN 1
#define QFIXEDSZ 4
#define RRFIXEDSZ 10
#define HFIXEDSZ 12

typedef struct
{
	unsigned id:16;		/* query identification number */
#ifdef WORDS_BIGENDIAN
	/* fields in third byte */
	unsigned qr:1;		/* response flag */
	unsigned opcode:4;	/* purpose of message */
	unsigned aa:1;		/* authoritive answer */
	unsigned tc:1;		/* truncated message */
	unsigned rd:1;		/* recursion desired */
	/* fields in fourth byte */
	unsigned ra:1;		/* recursion available */
	unsigned unused:1;	/* unused bits (MBZ as of 4.9.3a3) */
	unsigned ad:1;		/* authentic data from named */
	unsigned cd:1;		/* checking disabled by resolver */
	unsigned rcode:4;	/* response code */
#else
	/* fields in third byte */
	unsigned rd:1;		/* recursion desired */
	unsigned tc:1;		/* truncated message */
	unsigned aa:1;		/* authoritive answer */
	unsigned opcode:4;	/* purpose of message */
	unsigned qr:1;		/* response flag */
	/* fields in fourth byte */
	unsigned rcode:4;	/* response code */
	unsigned cd:1;		/* checking disabled by resolver */
	unsigned ad:1;		/* authentic data from named */
	unsigned unused:1;	/* unused bits (MBZ as of 4.9.3a3) */
	unsigned ra:1;		/* recursion available */
#endif
	/* remaining bytes */
	unsigned qdcount:16;	/* number of question entries */
	unsigned ancount:16;	/* number of answer entries */
	unsigned nscount:16;	/* number of authority entries */
	unsigned arcount:16;	/* number of resource entries */
} HEADER;

/*
 * Inline versions of get/put short/long.  Pointer is advanced.
 */
#define IRC_NS_GET16(s, cp) { \
	const unsigned char *t_cp = (const unsigned char *)(cp); \
	(s) = ((uint16_t)t_cp[0] << 8) \
	    | ((uint16_t)t_cp[1]) \
	    ; \
	(cp) += NS_INT16SZ; \
}

#define IRC_NS_GET32(l, cp) { \
	const unsigned char *t_cp = (const unsigned char *)(cp); \
	(l) = ((uint32_t)t_cp[0] << 24) \
	    | ((uint32_t)t_cp[1] << 16) \
	    | ((uint32_t)t_cp[2] << 8) \
	    | ((uint32_t)t_cp[3]) \
	    ; \
	(cp) += NS_INT32SZ; \
}

#define IRC_NS_PUT16(s, cp) { \
	uint16_t t_s = (uint16_t)(s); \
	unsigned char *t_cp = (unsigned char *)(cp); \
	*t_cp++ = t_s >> 8; \
	*t_cp   = t_s; \
	(cp) += NS_INT16SZ; \
}

#define IRC_NS_PUT32(l, cp) { \
	uint32_t t_l = (uint32_t)(l); \
	unsigned char *t_cp = (unsigned char *)(cp); \
	*t_cp++ = t_l >> 24; \
	*t_cp++ = t_l >> 16; \
	*t_cp++ = t_l >> 8; \
	*t_cp   = t_l; \
	(cp) += NS_INT32SZ; \
}

extern int irc_res_init(void);
extern int irc_dn_expand(const unsigned char *msg, const unsigned char *eom,
			 const unsigned char *src, char *dst, int dstsiz);
extern int irc_dn_skipname(const unsigned char *ptr, const unsigned char *eom);
extern unsigned int irc_ns_get16(const unsigned char *src);
extern unsigned long irc_ns_get32(const unsigned char *src);
extern void irc_ns_put16(unsigned int src, unsigned char *dst);
extern void irc_ns_put32(unsigned long src, unsigned char *dst);
extern int irc_res_mkquery(const char *dname, int class, int type, void *buf, int buflen);

#endif
